The Opteron X12 6164 runs at 1.7GHz and has 16MB of cache and it costs $797, while the 6136 is clocked at 2.4GHz, packs 18MB of cache and costs $808. The slower version runs on just 65W of power, while the 2.4GHz model consumes 105W, which sounds quite impressive.

The X12 6176 is clocked at 2.3GHz and it has 18MB of cache, but at $1,491 it's the priciest of the lot. The 2.2GHz 6174 costs $1,250, while the 2.1GHz 6172 is priced at $1,060.